Chemically activated warming devices often employ metal reactants (e.g., iron powder) that are oxidized in the presence of air and moisture. Because the oxidation reaction is exothermic and generates heat, the resulting device may provide warmth when activated. The warming device typically contains other chemical reactants to facilitate the exothermic reaction, such as activated carbon and metal halides. The activated carbon acts as a catalyst to facilitate the exothermic reaction, while the metal halide removes surface oxide films on the metal powder to allow the reaction to proceed to a sufficient extent. Unfortunately, various problems exist with conventional chemically activated warming devices. For example, the oxidizable metal and carbon components of the device are stiff and inflexible. Consequently, during use, it is often difficult to fold and conform the thermal device to a body part. As such, a need currently exists for a technique of improving the conformability and flexibility of chemically activated thermal devices.